Four-wave interaction in gas and vacuum: definition of a third-order nonlinear effective susceptibility in vacuum: $\chi$ vacuum(3)

TL;DR

This paper explores the nonlinear interaction of light in vacuum using semiclassical methods, introducing a third-order effective susceptibility to describe four-wave mixing effects predicted by quantum electrodynamics with ultrashort laser pulses.

Contribution

It develops a classical nonlinear optics framework for vacuum, defining a third-order nonlinear susceptibility to facilitate the study of four-wave mixing in vacuum.

Findings

Defined a third-order nonlinear susceptibility for vacuum.

Provided a semiclassical approach to four-wave mixing in vacuum.

Suggested potential for experimental verification with ultrashort laser pulses.

Abstract

Semiclassical methods are used to study the nonlinear interaction of light in vacuum in the context of four wave mixing. This study is motivated by a desire to investigate the possibility of using recently developed powerful ultrashort (femtosecond) laser pulses to demonstrate the existence of nonlinear effects in vacuum, predicted by quantum electrodynamics (QED). An approach, similar to classical nonlinear optics in a medium, is developed in this article. A third-order nonlinear effective susceptibility of vacuum is then introduced.